Internal transcribed spacer 2 (ITS2) barcodes: A useful tool for identifying Chinese Zanthoxylum

Area of Science:

• Botany
• Molecular Biology
• Genetics

Background:

• The genus Zanthoxylum (Rutaceae) is economically and medicinally important in Asia.
• Morphological similarities among Zanthoxylum species cause misidentification, impacting herbal markets and conservation.
• Accurate species identification is crucial for Zanthoxylum resource management.

Purpose of the Study:

• To evaluate DNA barcoding regions for identifying Chinese Zanthoxylum species.
• To determine the most effective DNA barcode for Zanthoxylum species discrimination.

Main Methods:

• Investigated three DNA barcoding regions: ITS2, ETS, and trnH-psbA.
• Analyzed 69 accessions of 13 Chinese Zanthoxylum species.
• Assessed PCR success, divergence, barcoding gaps, and identification efficiency using BLAST and phylogenetic methods.

Main Results:

• The ITS2 region achieved 100% correct identification rate for Chinese Zanthoxylum species.
• ITS2 exhibited significantly higher intra- and interspecific divergence compared to other regions.
• Phylogenetic analysis confirmed ITS2's strong discriminatory power at and below the species level.

Conclusions:

• ITS2 is a highly effective DNA barcoding region for identifying Chinese Zanthoxylum species.
• This finding supports accurate authentication and management of Zanthoxylum genetic resources.
• The study validates ITS2 for germplasm collection analysis and conservation efforts.